I've been trying for months to upgrade my Ubuntu 8.10 to 10.04 and have been told that I cannot because of my ATI Radeon Xpress M200 card. I finally got tired of not being able to get things from the repository, so I did a clean install from a CD. I have a 64-bit laptop. The clean install went fine and 10.04 seems to have no problems with the ATI card.

Why was the upgrade telling me it couldn't do it? I thought I would have to scrap this laptop and get another. In fact, I did buy another one with 10.04 as a backup for when this one finally quit.

If you do not have any particular software which requires a long post-installation tuning or setting up specific stuff (like remote licence server) it is always appropriate to perform a clean install (testing a live CD/DVD before). In this case you eliminate possible risk of update script's failures.

I prefer clean installation because it is much easier to restore all necessary data and configuration files (for Firefox, Thunderbird, Skype etc. by copying hidden directories) than in Windows systems.

I have been using Ubuntu and other flavors of Linux for several years now, and I always found that an upgrade is not a good idea. I always had much better results with an actual new install. When doing that, I also take the time to make yet another GOOD backup, and review all the applications i currently have installed. Most of the time, I will end up with only 50% of the installed applications that are actually required, the rest, being useless pieces of code, that will usually slow my computer down, or cause glitches and problems.

The only time an upgrade is worth it is when the software manufacturer will require that the previous version be installed in order to install itself. This can be the case for Microsoft Windows, but Linux is not an issue. and Even applications that you may buy will usually not require a re-licensing under Linux. Windows is a different game, all together.